Phantomx Reactor arm behaves differently in simulation and in practice

Hi everyone!

I've just recently got into Robotics and the first assignment i've received was to play around with the phantomx reactor arm

Anyway, i've set up the robot arm to work with Moveit. I've also created a python script which lets the robot draw a circle using the ComputeCartesianPath() method from Moveit.
When i'm running this code on the Rviz simulator it works just fine. The fraction of the plan is 1.0. All is good.
However, when i run the code on the actual robot, the returned fraction is only 0.48, and the robot only performs parts of the motion.

What could be the cause of this difference between simulation and reality? I've had my supervisor triple checked the code and made sure it was okay, so that should not have caused the issue.

I'm not familiar with Moveit, can you tell us a little more about your setup? Are you running ROS/pass through firmware on the ArboitX and controlling from the computer, or are you writing custom firmware for the ArbotiX?